Some products which have been available for use as “cat litter” or for other moisture (liquid) absorbing purposes, are formed from clay based materials and are non-organic with the resulting problem that they will not decompose. In addition they have the added disadvantage of depositing clay powder on the paws of cats which is subsequently transferred to floor surfaces leaving tracks. In addition such products result in the continued use of mineral resources whilst more recently certain cultivated pasture crops have been unnecessarily harvested and used merely for the purposes of “cat litter”.
In the case of paper fuel it may be composed of a relatively high percentage of paper. Whilst paper combusts readily it cannot be used in its basic form as it either burns too quickly in its loose sheet form or will not burn satisfactory when in the form of a thick mass. In addition, it is important to consider the physical transportation of recyclable paper in its normal form from collection zones to points of use for heating and/or cooking.
As a result of a heightening of community awareness, the supply of paper for recycling has increased to such a degree that it, in many cases, far exceeds the demand for conventional products made from such recycled paper, and as a result the excess is disposed of by landfilling or exported usually at the cost of the country.
In International patent application no. PCT/AU91/00308 (Publication no. WO92/01833) there is disclosed a process and an apparatus for the production of paper products, such as “cat litter” or paper fuel, comprising reducing paper to a particulate form by shredding and grinding, conveying the particles of paper as a layer on a first conveyor firstly beneath a first levelling and compacting roller and thereafter beneath a first set of water sprays, before discharging from the conveyor onto a second conveyor through a rearwardly inclined transfer chute to invert the layer during transfer. The inverted layer on the second conveyor passes firstly beneath a second levelling and compacting roller and thereafter beneath a second set of water sprays. The paper product is completed by extruding the paper and water mixture and cutting the extruded mix into pellets before subjecting the pellets to dehydration. In the case of paper product to be used as paper fuel, the paper is mixed with coal dust.
In International patent application no. PCT/AU98/00206 (publication No. WO98/43805) there is disclosed a process and an apparatus for the production of paper products, such as “cat litter” or paper fuel, comprising reducing paper to a particulate form by shredding and grinding, conveying the particles of paper from a hopper as a layer on a first conveyor firstly beneath a levelling and compacting roller and thereafter beneath a set of water sprayers, before discharging from the conveyor onto a second conveyor with the assistance of a rearwardly baffle plate to invert the layer during transfer. The inverted layer on the second conveyor passes to a third conveyor belt which moves through a ring which has the effect of wrapping the belt over itself and around the mix to form a tunnel enveloping and compacting the mix. The paper product is subsequently extruded and again cut into pellets before subjecting the pellets to dehydration, and in the case of paper product to be used as paper fuel, the paper is mixed with coal dust. The bottom of the hopper contains a plurality of rotatable worm screws for discharging the paper evenly across the conveyor, whilst rotatable paddle type agitators are also contained in the bottom of the conveyor to prevent the particulate paper from agglomerating into lumps.
The processes and apparatus referred to above has proved effective for the production of paper products, but some difficulties have been encountered in effectively compacting or compressing the paper and water mixture for extrusion and subsequent cutting into pellets, and, although the use of a conveyor moving through a ring to wrap the belt over itself and around the mix to form a tunnel enveloping and compacting the mix, and as disclosed in publication no. WO98/43805, can be effective it is not always consistent whilst frictional forces between the belt and the ring can cause accelerated belt wear, whilst also necessitating the selection of a more highly powered motor for the belt drive than would be required to merely drive the conveyor belt and thus increasing the plant cost.